1. Field of the Invention
The present invention relates to a plant diagnostic apparatus and particularly to a diagnostic apparatus which estimates a failure occurring in a power plant or the like and displays simulation value for progress of such failure for convenience of taking measures.
2. Description of the Prior Art
FIG. 1 is a block diagram showing a diagnostic apparatus of the prior art. In this figure, an electronic computer 1 comprises an input processing part 3 for inputting a process quantity from a plant 2, a fault detecting part 4 for detecting a fault in the input data, a cause diagnosing part 5 for estimating a cause of the fault from fault phenomenon detected by the fault detecting part 4, a plant transition value data, storing and processing part 6 for storing plant transition data, a plant transition value data file 7, a fault data retrieving part 8, a cause estimating image generating part 9 and a display processing part 11 for displaying data to a display unit 10.
FIG. 2 is a flowchart indicating processes for displaying cause estimation and estimated cause in the plant diagnostic apparatus of the prior art.
In the plant diagnostic apparatus of the prior art, input data from the plant 2 is subjected to an input process (step ST1) in the input processing part 3 and is sent to the plant transition value data storing and processing part 6 for carrying out a plant transition value data storing process (step ST2) in order to store the transition data in a plant transition data file 7. The input data having completed the input process (steps ST1 and ST2) is then sent to the fault detecting part 4 to monitor changes in the value of input data. If the input data deviates from a normal condition, a fault detection process (step ST3) is carried out to detect the occurrence of a fault condition. If a fault condition is detected, the cause estimation process (step ST5) is carried out in the cause estimating part 5. When a fault condition is not detected, monitoring is continued.
The cause estimating part 5 estimates a cause of a detected fault event. The cause data estimated here, together with the fault data having passed a fault period data retrieving process (step ST6) under the fault condition in the fault data retrieving part 8, are sent to the cause estimating image generating part 9 and subjected to a cause estimation image generating process (step ST7). An image generated is displayed (step ST8) on the display unit 10 through the display processing unit 11.
The plant diagnostic apparatus of the prior art has arrangements described above and has the following problems when the estimated cause is displayed.
(a) It has been impossible to know whether or not the plant data has truly been changed to the detected condition by the estimated cause. PA0 (b) It is impossible to know the plant conditions under normal operation. PA0 (c) It is impossible to know how the plant condition changes when counter measures are taken to compensate for faults.